James Kirkup is The Telegraph's Executive Editor (Politics). He was previously the Telegraph's Political Editor and has worked at Westminster since 2001.

George Osborne, Chuka Umunna and Child Benefit: a political duel has begun

Since joining the Treasury Select Committee in the summer, Chuka Umunna, a new Labour MP and aide to Ed Miliband, has made a habit of asking witnesses about their own personal experience and knowledge of Treasury policies and their consequences. Typically, this involves asking a senior official or minister if they could live on benefits, or what difference cuts have made to their lives.

The implication, of course, is that ministers and officials are well-paid fatcats with no conception of “real” life, while Mr Umunna, (a former lawyer now paid a mere £65k a year as MP for Streatham) is speaking for the man on the street. As tactics go, it’s a bit crude and tends to obscure the rather more interesting and intelligent (but less populist) questions he also asks.

Still, true to form, he’s just tried the same routine on George Osborne, asking the Chancellor (salary: £130k; estimated personal worth: £4 million) how his austerity package will affect his own life.

Mr Osborne suggested that Mr Umunna had chosen to “play the man not the ball”. He also rather pointedly congratulated the MP on his appointment as Mr Miliband’s aide, and challenged him to explain how Labour proposed to reduce the deficit. Mr Umunna in turn told the Chancellor he was there to answer questions, not ask them.

Throughout, the tone of the exchange was not so much frosty as sub-zero.

The TSC is often a place for new MPs to make their name by firing darts at chancellors and other mighty servants; several of today’s ministers cut their teeth on Gordon Brown’s leathery hide on the committee.

Mr Umunna is an impressive and ambitious young man. Mr Osborne is a lethally effective political operator. I suspect that today marks the start of an intriguing political duel. Future exchanges between these two will be well worth watching.